AMD Ryzen 5 & 7 CPU Cooler Round Up

Ryzen thermal testing, tCTL offset and other info

Some of AMD's Ryzen CPUs come with a thermal offset, which means that select SKUs list higher readings on temperature monitoring utilities than are actually present on the CPU. AMD states that these thermal control (tCTL) offsets are designed to adjust fan profiles, allowing fans to spin faster on Ryzen CPUs with higher TDPs and at lower speeds for Ryzen CPUs that have lower TDPs.

In simple terms, this means that 95W CPUs like the R7 1800X, 1700X and R5 1600X will present readings that are 20 degrees higher than what is actually present on the CPU, making the CPU seem a lot hotter and provides a lot of confusion when it comes to heatsink testing on Ryzen.

For example, if an 1800X or 1700X present a load temp of 58 degrees in Ryzen Master it is actually sitting at 38 degrees in silicon, which means that AMD is technically lying about Ryzen's temps on select SKUs. This is not necessarily a bad thing from a certain perspective, as it effectively forces a more aggressive fan profile for AMD's 95W Ryzen parts, though more information at launch would have been appreciated.

On the 65W Ryzen 7 1700, Ryzen 5 1600 and Ryzen 5 1500X there is no tCTL offset, which means that CPU temperatures will be shown correctly on temperature monitoring applications like Ryzen Master.

Product Name

True Junction Temp (Example)

tCTL Offset for Fan Policy

Temp Reported by tCTL

AMD Ryzen 7 1800X

38°C

20°C

58°C

AMD Ryzen 7 1700X

38°C

20°C

58°C

AMD Ryzen 7 1700

38°C

0°C

38°C

In our testing, we found that Ryzen was able to run properly without any downclocking or other issues until our R7 1800X went over 90 degrees for a sustained period (70 degrees when considering the tCTL offset), causing the system to shutdown if this temperature was exceeded for more than a few moments.

This means that Ryzen's thermal limits are at around 70 degrees, though users will have to adjust this temperature depending on their CPU's tCTL offset and their chosen monitoring tools.

Ryzen Master - (Latest version)

The newest iteration of AMD's Ryzen Master utility has now made things much easier for measure Ryzen's load temperatures, now taking away AMD's tCTL offset and presenting the CPU's true thermals under load.

This means that users of all Ryzen CPUs will simply need to keep Ryzen under 70 degrees under load when measuring the heat of your CPU using this utility, taking away a lot of unnecessary confusion.

In our testing, we will test our Ryzen CPUs had a thermal limit of 70 degrees celsius, which is the temperature where the CPU would soon start downclocking or quickly cause the system to shut down.

Such a shame for a low temp limit. This kinda hurts the argument that AMD platform is cheaper right now since you need to invest into a strong cooler to maintain the OCs most people aim for

But at the same time how many people overclock on X99 without a large cooler.

I do agree with you, raising the thermal limit with Ryzen 2 would be fantastic, as it could allow even basic air cooling to handle higher overclocks/voltages. If it were 80 Degrees I think even the Cryorig H7 would have passed OC testing on the 8-core.Quote

Such a shame for a low temp limit. This kinda hurts the argument that AMD platform is cheaper right now since you need to invest into a strong cooler to maintain the OCs most people aim for

I use the $25 Hyper T4 to cooler my R7 1700 at 3800-3900mhz @ 1.4V and it seems to work just fine, granted I've upgraded the fan to a 140mm High Pressure Venturi fan, but it's probably not too much better than the stock fan. fan ran at 100% RPM, controled by a Sentry Mix 2 fan controller, super handy to have btw

Rarely breaks 60C running in a hot shed.

I would highly recommend a deepcool gammax 400 instead though, as it has cut outs to fit RAM, i wouldn't be able to put RAM into the 1st slot if I needed to upgrade to 32GBs, since I can't turn the heatsink on AM4 anyways.Quote

Tbh I'd think if your looking at overclocking either Intel or AMD you'd most lightly look at an AIO

most enthusiasts would, but not everyone will. Especially those people buying the 1600/x CPUs. Either way, spending all that money on a cooler hurts the "cheaper" argument people, including me, would use. It'll still end up cheaper of course than an intel system, but still more money is still more money.Quote

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